Ball overturning: the assembly should be correct, the operation should be stable, and the throttle valve should not be used; the ball should be repaired in time after the punching, the replacement seal seat is used for throttling, and the sealing surface is damaged: no throttling is allowed.
The sealing surface is crushed: the bolts at the valve seat should be even and the force should be small. It is better to tighten it several times. Do not tighten too much too tightly at one time. The damaged sealing surface can be repaired by grinding.
There is no pre-tightening pressure on the sealing surface: the sealing surface of the valve seat should be checked regularly for pre-tightening pressure. If the sealing surface is leaky or the contact is too loose, the sealing surface of the valve seat should be pressed a little. If the pre-compression spring fails, the wrench, valve stem and sphere should be replaced. The gap at the joint is large, the wrench has reached the closing position, and the rotation angle of the ball is less than 90°, resulting in leakage: the joint of the wrench, the stem and the ball of the limited position mechanism should be repaired when the connection is loose and the clearance is too large. Adjust the limit block, eliminate the advance angle of the wrench, and make the ball open and close correctly
The contact surface between the valve seat and the body is not smooth and worn, and the 0-ring damage causes the valve seat to leak: improve the contact surface smoothness of the valve seat and the body, reduce the number of valve seat disassembly, and replace the O-ring regularly.
Rubber seal aging, wear: rubber seal surface is replaced regularly
The sealing surface pressure ring is loose and damaged: when the pressure ring is loose, it should be retightened, and the damage and corrosion should be replaced.
The flow direction of the medium is wrong: the butterfly valve should be installed according to the flow direction arrow
Loosen the connection between the valve stem and the disc to make the valve not tight: remove the butterfly valve and repair the connection between the valve stem and the disc
The transmission and the stem are damaged, so that the sealing surface is not tight: repairs should be made and the damage should be replaced.
